Auto merge of #5718 - bundler:seg-reduce-gemfile-eval-count, r=indirect

Eval Gemfiles one fewer time when running `bundle install`

This is just a straight port of #4952 to master from `2-0-dev`.
Unfortunately, the Gemfile is still eval'ed twice when plugins are enabled.

lib/bundler/definition.rb

@@ -194,10 +194,19 @@ def missing_specs
       missing
     end
 
-    def missing_dependencies
+    def missing_dependencies?
       missing = []
       resolve.materialize(current_dependencies, missing)
-      missing
+      return false if missing.empty?
+      Bundler.ui.debug "The definition is missing #{missing.map(&:full_name)}"
+      true
+    rescue BundlerError => e
+      Bundler.ui.debug "The definition is missing dependencies, failed to resolve & materialize locally (#{e})"
+      true
+    ensure
+      @index = nil
+      @resolve = nil
+      @specs = nil
     end
 
     def requested_specs

lib/bundler/installer.rb

@@ -78,7 +78,7 @@ def run(options)
         return
       end
 
-      resolve_if_need(options)
+      resolve_if_needed(options)
       ensure_specs_are_compatible!
       install(options)
 
@@ -229,18 +229,11 @@ def create_bundle_path
         "because a file already exists at that path. Either remove or rename the file so the directory can be created."
     end
 
-    def resolve_if_need(options)
+    def resolve_if_needed(options)
       if !options["update"] && !options[:inline] && !options["force"] && Bundler.default_lockfile.file?
-        local = Bundler.ui.silence do
-          begin
-            tmpdef = Definition.build(Bundler.default_gemfile, Bundler.default_lockfile, nil)
-            true unless tmpdef.new_platform? || tmpdef.missing_dependencies.any?
-          rescue BundlerError
-          end
-        end
+        return if @definition.nothing_changed? && !@definition.missing_dependencies?
       end
 
-      return if local
       options["local"] ? @definition.resolve_with_cache! : @definition.resolve_remotely!
     end
 

lib/bundler/source/path.rb

@@ -35,10 +35,12 @@ def initialize(options)
       end
 
       def remote!
+        @local_specs = nil
         @allow_remote = true
       end
 
       def cached!
+        @local_specs = nil
         @allow_cached = true
       end
 

lib/bundler/source/rubygems.rb

@@ -31,6 +31,7 @@ def remote!
       end
 
       def cached!
+        @specs = nil
         @allow_cached = true
       end
 

spec/install/gemfile/lockfile_spec.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+RSpec.describe "bundle install with a lockfile present" do
+  let(:gf) { <<-G }
+    source "file://#{gem_repo1}"
+
+    gem "rack", "1.0.0"
+  G
+
+  subject do
+    install_gemfile(gf)
+  end
+
+  context "gemfile evaluation" do
+    let(:gf) { super() + "\n\n File.open('evals', 'a') {|f| f << %(1\n) } unless ENV['BUNDLER_SPEC_NO_APPEND']" }
+
+    context "with plugins disabled" do
+      before do
+        bundle! "config plugins false"
+        subject
+      end
+
+      it "does not evaluate the gemfile twice" do
+        bundle! :install
+
+        with_env_vars("BUNDLER_SPEC_NO_APPEND" => "1") { expect(the_bundle).to include_gem "rack 1.0.0" }
+
+        # The first eval is from the initial install, we're testing that the
+        # second install doesn't double-eval
+        expect(bundled_app("evals").read.lines.to_a.size).to eq(2)
+      end
+
+      context "when the gem is not installed" do
+        before { FileUtils.rm_rf ".bundle" }
+
+        it "does not evaluate the gemfile twice" do
+          bundle! :install
+
+          with_env_vars("BUNDLER_SPEC_NO_APPEND" => "1") { expect(the_bundle).to include_gem "rack 1.0.0" }
+
+          # The first eval is from the initial install, we're testing that the
+          # second install doesn't double-eval
+          expect(bundled_app("evals").read.lines.to_a.size).to eq(2)
+        end
+      end
+    end
+  end
+end

spec/spec_helper.rb

@@ -46,7 +46,6 @@
 FileUtils.rm_rf(Spec::Path.gem_repo1)
 ENV["RUBYOPT"] = "#{ENV["RUBYOPT"]} -r#{Spec::Path.root}/spec/support/hax.rb"
 ENV["BUNDLE_SPEC_RUN"] = "true"
-ENV["BUNDLE_PLUGINS"] = "true"
 
 # Don't wrap output in tests
 ENV["THOR_COLUMNS"] = "10000"